This Monday morning I got out of bed before 3am to view the rare sight of a ‘red’ moon. The eclipse started at around 1.10am (BST) and the moon was completely within the shadow of the earth from 3.11am to 4.24am. It ended at 6.24am when the moon left the shadow of the Earth. It was a rare celestial event as the lunar eclipse coincided with a so-called ‘supermoon’ which occurs when the Moon is in the closest part of its orbit to Earth, meaning it appears larger in the sky. Although from my viewpoint it didn’t look particularly big in the sky. The eclipse was visible in Wirral along with the rest of Europe as well as North and South America and West Africa. From the UK, there was a clear view as the Moon passed through the Earth’s shadow in the early hours of Monday morning.
The moon looks rust-coloured during a total lunar eclipse giving rise to its nickname ‘Blood Moon’. In a total lunar eclipse, the Earth, Sun and Moon are almost exactly in line with each other, the Moon being on the opposite side of the Earth from the Sun. As the full Moon moves into our planet’s shadow, it dims dramatically but usually remains visible, lit by sunlight that passes through the Earth’s atmosphere. As this light travels through our planet’s atmosphere, the green to violet portions get filtered out more than the red portion, with the result that light reaching the lunar surface is predominantly red in colour. From our view point the Moon appeared to be red brick-coloured. The moon in this phase has a completely different appearance from its normal colour when its surface normally directly reflects light from the sun. Whilst a ‘normal’ moon can appear very bright it only reflects between 3 and 12 percent of the sunlight that hits it. The perceived brightness of the moon from Earth depends on where the moon is in its orbit around the planet.
The so called ‘supermoon’ appears 7-8% larger in the sky. It occurs when a full or new moon coincides with a Moon that is nearing its minimum distance or ‘perigee’ to Earth. The Moon takes an elliptical orbit around Earth, which means that its average distance changes from as far as 405,000km known as its ‘apogee’ to as close as 363,000km at the ‘perigee’.
As the eclipse began the Moon entered the lightest part of the Earth’s shadow, known as the penumbra, and adopted a yellowish colour. At 3:11am (BST) the Moon completely entered the umbra – the inner dark mass of the Earth’s shadow. The point of greatest eclipse occurred at 3:47am (BST), when the Moon was closest to the centre of the umbra.
I have to admit that I struggled with my 400mm telephoto lens to get a good picture of the red moon. I’ve managed to get a few shots which accompany this article. This phenomenon was last observed in 1982 and it will not be back for another 18 years until 2033. I’ll practice my astronomical photography a little more by then.